2012-03-15

Spirit Sol 1136

Let's see, we're back on Spirit now, so we're driving around ... oh, yeah, Home Plate! Or, rather, Mitcheltree Ridge, where the science team thinks outliers of Home Plate material are to be found. Today Terry and I are driving her over there.

And we're doing that a little more carefully than usual. The original path we'd planned for her would have taken us through a scattering of 10cm rocks, which we're nervous about dragging her anchor through. But then we spot an alternate destination that requires less turning and offers a clear path -- so there we head.

We're also nervous about something else. Yesterday's drive ended in some softer soil, and we found that she's turning more sluggishly in this stuff. With shades of the rover-eating Tyrone soil expanse haunting our memories, we make some very conservative choices. The soil seems to change back to a friendlier consistency a couple of meters away -- but it's so hard to be sure of these things, when all you have are visual cues. The absence of little ripples is our hint that the soil turns firmer.[1] It's just an educated guess, but sometimes that's all you have. So we argue a bunch, make some tweaks to the sequence, cross our fingers, and send the sequence to Mars.

[Next post: sol 1141, March 20.]

[1] This hypothesis was later confirmed by the science team. We'd noticed the pattern, but at this time we hadn't thought to ask them.